Acronis os selector 8.0 User Manual
2.6 Managing
Partitions
2.6.1
Setting an Active Partition
If you do not have a boot manager but you have created several primary
partitions, then you must select a partition from which the operating system
will be booted. There is a status flag for that in the partition table. This flag
should be on only for one partition, and it should be a partition and not an
unused entry or a reference to the partition table.
partitions, then you must select a partition from which the operating system
will be booted. There is a status flag for that in the partition table. This flag
should be on only for one partition, and it should be a partition and not an
unused entry or a reference to the partition table.
Some modern BIOSes check the partition table to see if there is any active
partition in it before passing control to MBR.
partition in it before passing control to MBR.
Make sure that the partition is formatted and contains an operating system before
setting it as active.
2.6.2
Accessing the Same Files from Multiple Operating Systems
There are several basic differences between primary and logical partitions (it
refers mainly to the FAT partitions):
refers mainly to the FAT partitions):
• Most operating systems can boot only from a primary partition (excluding
OS/2, Linux, and with some limitations and with help of Acronis OS
Selector, Windows 95 OSR2, 98, and ME).
Selector, Windows 95 OSR2, 98, and ME).
• Some operating systems recognize only one primary partition and ignore
all others (OS/2).
• All boot managers, except the Acronis OS Selector, must be installed only
on the primary partition of the first hard disk.
Considering these limitations one can decide which partitions to use for what
purposes. Primary partitions are best used to boot operating systems and
store system folders and files only. On the other hand, logical partitions can
be used to store all data, because they will be accessible by the operating
systems. If you are planning to install many different operating systems on
your computer, then those that can be booted from logical partitions are
better installed there to save primary partition space.
purposes. Primary partitions are best used to boot operating systems and
store system folders and files only. On the other hand, logical partitions can
be used to store all data, because they will be accessible by the operating
systems. If you are planning to install many different operating systems on
your computer, then those that can be booted from logical partitions are
better installed there to save primary partition space.
2.6.3
Efficiency of Disk Space Usage
If you have a large hard disk, but must use the FAT file system, then you
should know some of its peculiarities to use the disk space more efficiently.
As previously discussed, the main FAT feature is breaking the partition into
clusters of fixed size ranging from 512 bytes to 64 kilobytes.
should know some of its peculiarities to use the disk space more efficiently.
As previously discussed, the main FAT feature is breaking the partition into
clusters of fixed size ranging from 512 bytes to 64 kilobytes.
In FAT16, 16-bits are reserved to store numbers of clusters, so the maximum
number of clusters is 65525. The result is that the bigger the partition size
the bigger the cluster is needed, and the maximum partition size is about 4
gigabytes. However bigger cluster size results in higher hard disk space
number of clusters is 65525. The result is that the bigger the partition size
the bigger the cluster is needed, and the maximum partition size is about 4
gigabytes. However bigger cluster size results in higher hard disk space
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Chapter 2 : Basic Information